The present invention relates to a method and apparatus for high-precision straightness and flatness measurements across objects which are so large that available measuring rulers do not cover the distances to be measured.
Relatively easy-to-use, dependable and accurate measuring instruments such as electronic levels, laser and autocollimation systems etc. are currently available for straightness and flatness measurement of large objects even in factory premises. However there are major shortcomings in the devices used as reference and contact elements between the object of measurement and the instruments used to measure it when the objects are so large that they are not covered by available measuring rulers.